Television star Donna Air has hit back at critics who claim she has lost her Geordie accent during her relationship with the brother of the Duchess of Cambridge.

Air, who is currently appearing on BBC's Celebrity MasterChef, said she has been accused of abandoning her Newcastle dialect to give herself "more social cachet" during her on-off relationship with James Middleton.

Writing in the Mail on Sunday, the former Byker Grove actress said: "Some viewers seem more surprised by what came out of my mouth than what came out of my oven.

"My voice captured the public imagination in a way that even my surprise pink pudding simply didn't.

"Twitter decided I'd 'poshed up' on purpose, a slur to which there is only one possible answer: 'Haddaway man, you must be a reet wazzock if you reckon that.'

"Which roughly translated means: 'Oh come off it, you must be a bit of an idiot if you think so.'"

Viewers on Twitter had speculated Air had received elocution lessons since she began her relationship with Middleton.

Air added: " I'm an actress and a TV presenter: it's my job to speak clearly, to communicate effectively on and off camera. My home has been in London for 20 years now, longer than I lived in my native North East.

"I think it would be far weirder if I sounded the same as the 10-year-old Donna who starred in TV series Byker Grove asking PJ (Anthony McPartlin, now half of Ant and Dec) if he'd like to share a banana milk."

Air said she believed that criticism of her accent was rooted in snobbery and recalled a time she was asked if she had difficulty communicating with her then-boyfriend Damian Aspinall.

She wrote: "It's not a debate about my accent, it's a debate about how a Geordie girl whose life is supposed to have a gritty Northern narrative should find herself down and out in ... Knightsbridge.

"The perception of us Geordies has barely moved on since the days of Andy Capp. Even today people refer to the cult comic Viz and Jimmy Nail's Oz in Auf Wiedersehen, Pet, both of which are brilliantly funny but a bit out of date.

"Our accent, lampooned as 'whale song' by comedian Al Murray, is discussed as though it needs subtitles. Remember the furore in 2011 when Cheryl Cole lasted two weeks as a judge on American X Factor because US entertainment titans thought viewers couldn't understand her."

Air admitted that she changes her voice depending on who she is speaking to and said she is not alone in doing so, adding: " Warm and animated is different to firm and businesslike, but it's not a betrayal of regional roots, it's speaking fluent human."

The TV star denied "poshing up" and said the only coaching she ever received was when she started work on MTV early in her career.

On the controversy surrounding her dialect, she wrote: "The last time my voice came under this much scrutiny was in 2013 when I was reporting from Cowes Week and had recently met James Middleton. I'd mislaid my real accent, once again, on the way to get a pasty from Greggs was the general consensus of opinion."